NMR residual dipolar couplings (RDCs) are exquisite probes of protein structure and dynamics. A new solution NMR experiment named 2D SE2 J-TROSY is presented to measure N-H RDCs for proteins and supramolecular complexes in excess of 200 kDa. This enables validation and refinement of their X-ray crystal and solution NMR structures and the characterization of structural and dynamic changes occurring upon complex formation. Accurate N-H RDCs were measured at 750 MHz H-1 resonance frequency for 11-mer 93 kDa H-2,N-15-labeled Trp RNA-binding attenuator protein tumbling with a correlation time tau(c) of 120 ns. This is about twice as long as that for the most slowly tumbling system, for which N-H RDCs could be measured, so far, and corresponds to molecular weights of similar to 200 kDa at 25 degrees C. Furthermore, due to the robustness of SE2 J-TROSY with respect to residual H-1 density from exchangeable protons, increased sensitivity at H-1 resonance frequencies around 1 GHz promises to enable N-H RDC measurement for even larger systems.